Just what it was doing up there for more than 450 days is a mystery. Space.com: Exactly what the spacecraft, which is built by Boeing's Phantom Works division, was doing up there for so long is a secret. The details of the X-37B's mission are classified, as is its payload, with its mission overseen by the Air Force's Rapid Capabilities Office. This secrecy has led to some speculation, especially online and abroad, that the X-37B could be a space weapon of some sort -- perhaps a sophisticated satellite-killer. Some experts also suspect that the vehicle may be an orbital spy platform. The Air Force, however, has worked to tamp down such speculation, stressing repeatedly that the X-37B isn't doing anything nefarious hundreds of miles above the Earth's surface. "This is a test vehicle to prove the materials and capabilities, to put experiments in space and bring them back and check out the technologies," Richard McKinney, the Air Force's deputy undersecretary for...(Read Full Post)